RIYADH, Saudi Arabia (AP) — U.S. Secretary of State John Kerry sought to heal policy rifts with Saudi Arabia as hailed the kingdom's role as "the senior player" in the Middle East on Monday.

Kerry, speaking to employees at the U.S. Embassy in Riyadh ahead of meetings with Saudi Arabia's king and foreign minister, said Saudi Arabia had assumed the Arab leadership mantle from Egypt, which is distracted by major domestic unrest. He said strengthening the U.S.-Saudi partnership is critical to Mideast security and stability and cementing tentative political transitions around the region.

Saudi officials have expressed unhappiness with Washington's actions in Syria, its cautious warming with Iran and stance on Egypt's political turmoil, something Kerry has acknowledged in the past but played down as differences in "tactics" rather than in the end goal.

"Right now, we have some very important things to talk about to make certain that the Saudi Arabian-U.S. relationship is on track, moving forward and doing the things that we need to accomplish," Kerry told the embassy staffers. He listed a number of key areas, including Syria, Egypt and Iran, but also mentioned the Israeli-Palestinian peace process and the broader effort to tamp down "nihilism" that leads to extremist violence.

The Saudis have complained that the United States did not follow through on its threat to punish Syrian President Bashar Assad with military strikes for his government's use of chemical weapons. Last month, the Saudis won but turned down an elected seat on the U.N. Security Council, saying the body had proved itself largely meaningless because of its inability over two years to address the crisis in Syria. The Saudis also have watched with increasing nervousness as President Barack Obama has approved a cautious opening with their archrival Iran.

Eager to soothe the frustration, Kerry was effusive in his praise of the Saudis, noting a slow, but steady domestic transformation with new emphases on education and health. He did not specifically refer to recent protests against restrictions on women being able to drive but noted that people who live in the country can see that "there are things that are changing."

"It doesn't happen overnight, it takes time," he said.

On the regional strategic issues of particular interest to the United States, Saudi Arabia is now the major Arab power, Kerry said.

"The Saudis have the ability to be able to influence a lot of the things that we also care about," he said before meeting with Saudi King Abdullah and Foreign Minister Prince Saud al-Faisal. "The Saudis are very, very important to all of these things. The Saudis are really the sort of senior player, if you will, in the Arab world, together with Egypt. Egypt is in more of a transition, so Saudi Arabia's role is that much more important."

The comments came as the trial of ousted Egyptian President Mohammed Morsi began and then adjourned on Monday, a day after Kerry visited Cairo in a bid to get U.S.-Egypt relations on better footing. His brief stop in Egypt on Sunday was the highest-level visit by a U.S. official to the country since the military deposed Morsi in July and began a crackdown on his supporters, prompting the Obama administration to suspend hundreds of millions of dollars in aid. Restoring that assistance will require progress on returning to a democratically elected civilian government.

Looking to ease the concerns of Saudi Arabia and other Gulf Arab states, Kerry said in Cairo that all of them could count on America's support.

"The United States will be there for the defense of our friends and our allies," Kerry told reporters in Cairo. "We will not allow those countries to be attacked from outside. We will stand with them."

He specifically mentioned the Sunni majority states of Saudi Arabia, the United Arab Emirates, Qatar, Jordan and Egypt as nations, along with unspecified "others" in the region. Those others likely would include Israel, the strongest U.S. ally in the region. All have vested interests in seeing an end to the turmoil in Syria and are extremely wary of Shiite Iran's regional intentions.

"Iran will not get a nuclear weapon," Kerry said. "That is a promise by the president of the United States."

Kerry is in Saudi Arabia on the second leg of a 10-day tour through the Middle East, Europe and North Africa. From Riyadh, he will travel to Poland, Israel, the Palestinian Authority, Jordan, the United Arab Emirates, Algeria and Morocco before returning to Washington.